Re: [PATCH v20 18/23] NET: Store LSM netlabel data in a lsmblob

Netlabel uses LSM interfaces requiring an lsmblob and the internal storage is used to pass information between these interfaces, so change the internal data from a secid to a lsmblob. Update the netlabel interfaces and their callers to accommodate the change. This requires that the modules using netlabel use the lsm_id.slot to access the correct secid when using netlabel. Reviewed-by: Kees Cook <keescook(a)chromium.org&gt; Reviewed-by: John Johansen <john.johansen(a)canonical.com&gt; Acked-by: Stephen Smalley <sds(a)tycho.nsa.gov&gt; Signed-off-by: Casey Schaufler <casey(a)schaufler-ca.com&gt; Cc: netdev(a)vger.kernel.org --- include/net/netlabel.h | 8 +-- net/ipv4/cipso_ipv4.c | 27 ++++++---- net/netlabel/netlabel_kapi.c | 6 +-- net/netlabel/netlabel_unlabeled.c | 79 +++++++++-------------------- net/netlabel/netlabel_unlabeled.h | 2 +- security/selinux/hooks.c | 2 +- security/selinux/include/security.h | 1 + security/selinux/netlabel.c | 2 +- security/selinux/ss/services.c | 4 +- security/smack/smack.h | 1 + security/smack/smack_lsm.c | 5 +- security/smack/smackfs.c | 10 ++-- 12 files changed, 65 insertions(+), 82 deletions(-)

diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c index 2eb71579f4d2..8182b923e802 100644 --- a/net/ipv4/cipso_ipv4.c +++ b/net/ipv4/cipso_ipv4.c @@ -106,15 +106,17 @@ int cipso_v4_rbm_strictvalid = 1; /* Base length of the local tag (non-standard tag). * Tag definition (may change between kernel versions) * - * 0 8 16 24 32 - * +----------+----------+----------+----------+ - * | 10000000 | 00000110 | 32-bit secid value | - * +----------+----------+----------+----------+ - * | in (host byte order)| - * +----------+----------+ - * + * 0 8 16 16 + sizeof(struct lsmblob) + * +----------+----------+---------------------+ + * | 10000000 | 00000110 | LSM blob data | + * +----------+----------+---------------------+ + * + * All secid and flag fields are in host byte order. + * The lsmblob structure size varies depending on which + * Linux security modules are built in the kernel. + * The data is opaque. */ -#define CIPSO_V4_TAG_LOC_BLEN 6 +#define CIPSO_V4_TAG_LOC_BLEN (2 + sizeof(struct lsmblob)) /* * Helper Functions @@ -1469,7 +1471,12 @@ static int cipso_v4_gentag_loc(const struct cipso_v4_doi *doi_def, buffer[0] = CIPSO_V4_TAG_LOCAL; buffer[1] = CIPSO_V4_TAG_LOC_BLEN; - *(u32 *)&buffer[2] = secattr->attr.secid; + /* Ensure that there is sufficient space in the CIPSO header + * for the LSM data. This should never become an issue. + * The check is made from an abundance of caution. */ + BUILD_BUG_ON(CIPSO_V4_TAG_LOC_BLEN > CIPSO_V4_OPT_LEN_MAX);

+ memcpy(&buffer[2], &secattr->attr.lsmblob, + sizeof(secattr->attr.lsmblob)); return CIPSO_V4_TAG_LOC_BLEN; }